In prior-art travelator arrangements people are moved on consecutive pallets, which form a continuous moving track. The pallets are connected to each other with a transmission chain, by which the pallets are moved. The chain is connected to a pallet with, for instance, a pin in the center part of the pallet, which pin is mounted on a bearing that allows the palette to rotate in relation to the pin. A problem in known arrangements is the sag of the transmission chain. The transmission chain sags between the fixing points of the consecutive pallets owing to the weight of the transmission chain. This sag is dependent on the tightening force of the transmission chain, which in turn is dependent on the number of people on the travelator and their distribution in the longitudinal direction of the travelator. The tightening force therefore can be of a different magnitude at different points of the transmission chain. That being the case, the sag is also of a different magnitude at different points of the conveyor. In addition, the tightening force varies as a consequence of the change in loading state as a result of the moving of the load. Passengers often walk along the conveyor and thus move from one pallet to another. When a passenger moves from one pallet to another, the rolling friction of both pallets changes. Likewise if a passenger happens to jump, a large backwards-and-forwards variation occurs in the rolling friction. In addition, when a passenger steps onto a pallet at the end of a travelator, the tightening force increases along the entire length of the travelator. Correspondingly, a passenger can step off the palette track of the travelator at either end of the track. The sag of the transmission chain of the travelator enables a small change in the distance between the pallets when the loading changes. Thus jerking in the longitudinal direction of the travelator is produced as a consequence of the aforementioned changes occurring in the loading. Such jerking impairs ride comfort.
In some situations the sag of the transmission chain can be hazardous because a sagging chain can reach to touch the stationary parts of the travelator, which causes noise and wear of the parts.
An object of the invention, among others, is to eliminate the aforementioned drawbacks of known arrangements. Other objects of the invention are to produce a more advanced people mover, preferably a travelator or the like, a more advanced method in the use of a people mover and a more advanced transmission chain. A further purpose of the invention is to produce a people mover with a more advanced transmission.
Advantages of the invention include, but are not limited to, a people mover in which the sag of the transmission chain is reduced; ride comfort is improved; noise is reduced; wear of parts is reduced and service life of the parts improved.
Furthermore, a travelator and a method may be achieved in which movement between the pallets, in the longitudinal direction of the travelator, can be reduced.